1. Field of the Invention
The present invention relates to a collating of image data. More particularly, the present invention relates to a pattern-collating device, a pattern-collating method and a pattern-collating program for identifying a line graphic such as a fingerprint, palm print and a character.
2. Description of the Related Art
As conventional collating device for recognizing a pattern of a line graphic such as a fingerprint, palm print or a character, a method of obtaining corresponding feature points by using feature points such as end points of a line or branch points and comparing them is described in Japanese Patent Application Laid-Open (referred to as JP-A hereinafter) Nos. 56-024675, 59-000778, 59-024384, 60-029875, 03-266187, 04-033065 and 04-043470.
However, the conventional technique mentioned above has the following disadvantages.
The method described in the JP-A Nos. 56-024675, 59-000778, 59-024384, 60-029875, 04-033065 and 04-043470 is a method to examine corresponding feature points and to identify based on the number of the corresponding feature points. Due to this, it is easy to form feature point pairs at locations at which feature points are crowded and there exist a problem that it is impossible to accurately compare the result if feature points have different densities among targets and/or models.
According to the method described in JP-A No. 03-266187, those with a large number of feature points adjacent to a certain feature point are invalidated to thereby deal with a case where the density of feature points is high. According to this method, however, if there are only locations at which the density of feature points is high, there exist a problem that it is impossible to identify.